A. Field of the Invention
The embodiments of the present invention relate to an actuator, and more particularly, the embodiments of the present invention relate to a latching sector motor actuator and to a failsafe sector motor actuator having an available operating range not limited to 90°.
B. Description of the Prior Art
Conventional rotary solenoids are broadly classified into two categories, namely, one that converts axial motion produced by electromagnetic attraction into rotary motion by use of a mechanical transforming mechanism utilizing an inclined groove and a ball, and the other that directly rotates a rotor of soft magnetic material by way of an electromagnet.
Regardless of this difference, however, the conventional rotary solenoids are attracted or rotate only in a direction in which magnetic reluctance reduces because their moving members are made of soft magnetic material. Therefore, they require a return spring or other similar apparatus to bring them back to the original position when not in operation.
It is of course possible to constitute a bi-directionally rotating system by combining two solenoids of uni-directional torque type, disposed opposite to each other. In principle, however, this system does not differ from the uni-directional solenoid.
In addition, the angular range of rotation of the conventional rotary solenoids has been limited to approximately 90° because of their design concepts. Further, they have required continued energizing or provision of a lock mechanism to maintain the operating position.
Thus, there exists a need for a latching sector motor actuator and a failsafe sector motor actuator having an available operating range not limited to 90°.
Numerous innovations for actuators have been provided in the prior art, which will be described below in chronological order to show advancement in the art, and which are incorporated herein in their entirety by reference thereto. Even though these innovations may be suitable for the specific individual purposes to which they address, nevertheless, they differ from the embodiments of the present invention in that they do not teach a latching sector motor actuator and a failsafe sector motor actuator having an available operating range not limited to 90°.
(1) U.S. Pat. No. 3,543,202 to Naybor.
U.S. Pat. No. 3,543,202—issued to Naybor on Nov. 24, 1970 in U.S. class 335 and subclass 229—teaches an indicator mechanism that is responsive to short duration direct current pulses to discretely indicate the nature of the last pulse applied. The indicator is magnetically latched in position and maintains the last position achieved, irrespective of possible power failure.
(2) U.S. Pat. No. 3,761,851 to Instant Inventor Nelson.
U.S. Pat. No. 3,761,851—issued to instant inventor Nelson on Sep. 25, 1973 in U.S. class 335 and subclass 253—teaches a two-pole armature that is located between two field poles, which provides a direct motion rotary actuator with high starting torque. Latching, non-latching, fail-safe return motion, and torque are of few of the many of modes.
(3) U.S. Pat. No. 3,886,545 to Skrobisch.
U.S. Pat. No. 3,886,545—issued to Skrobisch on May 27, 1975 in U.S. class 340 and subclass 373 teaches a segmental readout device that includes a support plate carrying seven rotatable magnetized indicator members in a spaced array adjacent to a front plate having openings to expose the indicator members. A magnetic back plate has forwardly extending magnetic cores integrally formed with the back plate and carrying cylindrical electromagnetic coils for actuating the indicator members. One group of lateral magnets in the array has diametrically opposite poles oriented oppositely from similar poles of another group of centered magnets. Coils associated with the lateral magnets are oppositely wound from the coils associated with the centered magnets. Rotational axes of the lateral magnets are perpendicular to the axes of the centered magnets. The orientation of the axes and pole winding of the coils effectively isolate adjacent magnetic circuits from each other so that it limits the ability of one magnet to cause rotation of any other magnet.
(4) U.S. Pat. No. 3,936,818 to Skrobisch.
U.S. Pat. No. 3,936,818—issued to Skrobisch on Feb. 3, 1976 in U.S. class 340 and subclass 373—teaches an electromagnetic indicator assembly that includes a nonmagnetic angle plate defining a support frame for axially parallel spaced rotors, each including a permanent magnet and a nonmagnetic plate circumferentially surrounding a portion of the magnet. The rotors carry symbols for display at window openings in the support frame. Another angle plate made of magnetic metal has stamped laterally spaced integral fingers defining magnetic cores carrying magnetizing coils axially perpendicular to the rotors. Ends of the cores serve as abutments for spaced edges of the rotor plates to stop rotation thereof. Adjacent cores are oppositely magnetized and adjacent rotors are oppositely magnetized to prevent rotation of adjacent rotors when any one rotor is selectively turned to display a symbol. The coils are energizable to hold the rotors latched against rotation in both stationary positions or energizable only for the purpose of turning a rotor to display a symbol, with the rotor returning to an original stationary position magnetically when the coil is de-energized.
(5) U.S. Pat. No. 3,970,980 to Instant Inventor Nelson.
U.S. Pat. No. 3,970,980—issued to instant inventor Nelson on Jul. 20, 1976 in U.S. class 335 and subclass 253—teaches a rotary actuator that provides rotation of its rotor over predetermined angles. The rotor is a cylindrical housing in which are cylindrically curved permanently magnetized poles spaced apart at their ends and surrounding a fixed armature. The armature has magnetic arms angularly disposed with respect to each other, which define fixed poles. Coils wound on the fixed poles generate magnetic fields when energized to drive the rotor. A holding coil is providable to hold the rotor stationary when the holding coil is energized. The armature may have fixed poles. The actuator is operatable in rotor latching or fail-safe return modes. Fixed stop members are usable to limit angular rotation of the rotor.
(6) U.S. Pat. No. 4,227,164 to Kitahara.
U.S. Pat. No. 4,227,164—issued to Kitahara on Oct. 7, 1980 in U.S. class 335 and subclass 230—teaches a rotary solenoid or similar electromagnetic rotating apparatus that is capable of smoothly rotating in both directions.
(7) U.S. Pat. No. 4,523,167 to Remington.
U.S. Pat. No. 4,523,167—issued to Remington on Jun. 11, 1985 in U.S. class 335 and subclass 230—teaches a bistable electromagnetic latch, particularly adapted for use with an electronic combination lock on a luggage case, which includes a magnetic member pivotally mounted for rotation between a pair of pole pieces. The magnetic member has first and second stable rotational positions at which each magnetic pole is adjacent to a different pole piece. A pair of oppositely wound coils are associated with the pole pieces and responsive to the momentary flow of electrical current therethrough for producing a magnetic flux that causes the magnetic member to rotate from one position to the other.
(8) U.S. Pat. No. 5,038,064 to Fiorenza.
U.S. Pat. No. 5,038,064—issued to Fiorenza on Aug. 6, 1991 in U.S. class 310 and subclass 116—teaches a limited angle torque actuator that produces a substantially constant torque. The actuator uses a core made from a highly permeable magnetic material, such as soft iron. In a preferred embodiment, ≧1 permanent magnet is/are attached to the outer surface of the cylindrical core. In another embodiment, the permanent magnets are spaced-apart from a stationary core to create an air-gap therebetween. When current flows through a coil wound on the stator, first and second stator poles are created, which interact with the permanent magnets to rotate the rotor assembly.
(9) U.S. Pat. No. 6,518,685 to Instant Inventor Nelson.
U.S. Pat. No. 6,518,685—issued to instant inventor Nelson on Feb. 11, 2003 in U.S. class 310 and subclass 191—teaches a multi-position actuator with three electromagnetic poles where the air-gap of selected pole(s) is/are made different from the remaining pole(s). The multi-position actuator includes a housing, an armature rotatably mounted in the housing, and three poles journaled around the armature. There is also a stop arm attached to the armature, which stops the rotation of the armature when the stop arm hits an adjacent stop. The stops are positioned within the housing to limit the rotation of the armature. The multi-position actuator forms either a fail safe actuator or a latching actuator by adjusting the spacing of the air-gap between the poles and the armature. When used with continuous rotation without the stop mechanism, the air-gap(s) of the pole(s) is/are adjustable in a repetitive manner to produce a useful magnetic torque.
(10) U.S. Pat. No. 6,967,422 B2 to Instant Inventor Nelson.
U.S. Pat. No. 6,967,422 B2—issued to instant inventor Nelson on Nov. 22, 2005 in U.S. class 310 and subclass 191—teaches a two-position rotary actuator that provides a latching or holding torque that is adjustable by altering magnetic properties of a selected pole member. The actuator also functions as a sector motor over a selected range of angular motion, and provides failsafe operation that returns the actuator to a starting position when electrical power is removed.
(11) U.S. Pat. No. 8,441,159 B2 to Instant Inventor Nelson.
U.S. Pat. No. 8,441,159 B2—issued to instant inventor Nelson on May 14, 2013 in U.S. class 310 and subclass 36—teaches a self-latching sector motor for producing a net torque from two integral independent sources where one is serviceable as a spare backup or paralleled for double net torque or used alternately for extended life operation. The self-latching sector motor includes a housing, a magnet-shaft assembly, and two pair of electromagnetic poles. The magnet-shaft assembly rotates within the housing. The two pair of electromagnetic poles extend fixedly and radially inwardly from the housing, towards the magnet-shaft assembly. The electromagnetic poles of an associated pair of electromagnetic poles are diametrically and magnetically opposed to each other, and each pair of electromagnetic poles are similarly poled to each other for North and South poles so as to provide the net torque to the magnet-shaft assembly that can be backed-up or doubled. The self-latching torque at the stops is achieved by restraining the magnet-shaft assembly from seeking a position of maximum flux.
It is apparent that numerous innovations for actuators have been provided in the prior art, which are adapted to be used. Furthermore, even though these innovations may be suitable for the specific individual purposes to which they address, nevertheless, they would not be suitable for the purposes of the embodiments of the present invention as heretofore described, namely, a latching sector motor actuator and a failsafe sector motor actuator having an available operating range not limited to 90°.